Start with the simplest fixes first
Most computer problems go away after a restart. Power off completely, wait 30 seconds, and turn it back on. This clears temporary files from memory and resets connections that may have stalled. If your computer is frozen and won't shut down normally, hold the power button for 10 seconds until the screen goes black.
If restarting doesn't work, check whether the problem is actually with your internet connection rather than your computer. Open a web browser and try to load a website you know exists. If nothing loads, restart your router by unplugging it for 30 seconds, plugging it back in, and waiting two minutes for it to fully restart. If websites still won't load but other devices on your network work fine, the problem is your computer's network settings, not the internet itself.
Before you do anything else, make sure your operating system and antivirus software are up to date. Outdated software is the source of most crashes, freezes, and slow performance. On Windows, go to Settings > Update & Security > Windows Update and click "Check for updates." On Mac, go to System Preferences > Software Update. Let any updates finish completely and restart if prompted.
Key Takeaways
- A full restart solves roughly half of all computer problems and should be your first step every time.
- Check your internet connection separately from your computer by testing on another device, because network problems feel like computer problems.
- Update Windows or macOS and your antivirus software before troubleshooting anything else, since outdated software causes crashes and slowness.
- If your computer is running slowly, check Task Manager (Windows) or Activity Monitor (Mac) to see which programs are using the most resources and close the ones you don't need.
- Malware and viruses require a dedicated antivirus scan, not a restart, and may need professional removal if your antivirus finds infections.
Identify what is actually broken
Before you can fix anything, you need to know what is wrong. Write down exactly what happens: Does the computer not turn on at all? Does it turn on but freeze before reaching the desktop? Does it reach the desktop but then freeze or crash? Does it run slowly? Does a specific program crash? The more specific you are, the faster you can find the real cause.
If your computer won't turn on, check the power cable first. Make sure it is plugged into both the computer and a working outlet. Try a different outlet if you have one. If the computer has a removable battery, remove it, wait 10 seconds, and reinstall it. If nothing happens after that, the power supply may have failed and you will need to take it to a repair shop.
If your computer turns on but gets stuck before the desktop appears, restart it and watch for error messages on the screen. Write down any message you see, even if it is just a code. These messages tell a technician exactly what went wrong. If you see a message about a hard drive error or a corrupted file, do not try to fix it yourself—take the computer to a repair shop, because the hard drive may be failing.
Check for malware and viruses
Malware and viruses cause crashes, slowness, pop-ups, and unexpected behavior. If your computer is behaving strangely, run a full antivirus scan. On Windows, Windows Defender is built in: go to Settings > Update & Security > Windows Security > Virus & threat protection > Manage settings and make sure "Real-time protection" is on. Then click "Scan options" and choose "Full scan." On Mac, use the built-in Malwarebytes or read Avast Free Security.
A full scan can take 30 minutes to several hours depending on how much is on your computer. Let it finish completely. If the scan finds infections, follow the prompts to remove them. After removal, restart your computer. If the antivirus finds many infections or cannot remove them, take your computer to a repair shop—some malware requires manual removal by a technician.
If you want a second opinion, Malwarebytes is a separate tool that catches things some antivirus programs miss. read the free version from malwarebytes.com, run a scan, and let it remove anything it finds. Do not pay for the premium version unless you want real-time protection; the free scan is enough for a one-time check.
Fix slowness by closing resource-heavy programs
If your computer is running slowly, something is using too much of your processor, memory, or hard drive. On Windows, press Ctrl + Shift + Esc to open Task Manager. Click the "Processes" tab and look at the columns labeled "CPU" and "Memory." The programs using the most resources are at the top. If you see a program you do not recognize or do not need, click it and click "End Task." Do not close anything labeled "System" or "Windows."
On Mac, press Command + Space, type "Activity Monitor," and press Enter. Click the "CPU" tab to see which programs are using the most processor power. Click a program you do not need and click the X button to close it. Again, do not close anything labeled "kernel" or "system."
If your hard drive is almost full, that also causes slowness. On Windows, right-click the C: drive in File Explorer and click "Properties" to see how much space is left. If the bar is mostly full, delete old files you no longer need, empty the Recycle Bin, and consider moving large files like videos to an external hard drive. On Mac, click the Apple menu > About This Mac > Storage to see what is taking up space.
Update drivers if a specific device is not working
A driver is software that lets your computer talk to a piece of hardware—your printer, graphics card, network adapter, or audio system. If a device suddenly stops working, the driver may be outdated or corrupted. On Windows, right-click the Start button, click "Device Manager," find the device that is not working, right-click it, and click "Update driver." Choose "Search automatically for updated driver software." Windows will search online and install the newest version if one exists.
If automatic update does not work, go to the manufacturer's website. For example, if your printer is not working, go to the printer maker's support page, search for your printer model, and read the latest driver. Run the installer and restart your computer. On Mac, drivers usually update automatically through Software Update, so check there first.
If updating the driver does not fix the problem, uninstall the driver completely, restart your computer, and let Windows reinstall it automatically. Right-click the device in Device Manager, click "Uninstall device," check the box that says "Delete the driver software for this device," and click "Uninstall." Restart, and Windows will reinstall the driver from scratch.
Clear your hard drive of temporary files
Temporary files pile up over time and can slow your computer or cause crashes. On Windows, press Windows key + I to open Settings, go to System > Storage > Temporary files, and click "Remove files." Windows will delete temporary internet files, recycle bin contents, and other junk. This usually frees up several gigabytes of space.
On Mac, temporary files are harder to find, but you can use the built-in Disk Utility to check for problems. Press Command + Space, type "Disk Utility," and press Enter. Click your hard drive name on the left, click "First Aid," and click "Run." Disk Utility will scan for errors and fix them automatically. This takes 10 to 30 minutes.
If your computer is still slow after clearing temporary files and closing resource-heavy programs, the hard drive itself may be failing. Back up your important files to an external drive or cloud storage when ready, then take your computer to a repair shop for a hard drive test.
Know when to take it to a professional
Some problems require a technician. Take your computer to a repair shop if the hard drive is making clicking or beeping sounds, if it will not turn on after you have checked the power cable, if it shows error messages about a hard drive failure, if it overheats and shuts down on its own, or if it has been infected with malware that your antivirus cannot remove.
Before you go, back up your important files if the computer will still turn on. Use an external hard drive or cloud storage like Google Drive or OneDrive. If the computer will not turn on at all, a technician can usually recover your files, but it costs more. Write down what the problem is and when it started so you can explain it clearly.
Repair costs vary widely depending on what is broken. A hard drive replacement usually costs $150 to $300. A motherboard replacement costs $200 to $500. A virus removal costs $50 to $150. Ask for a quote before you authorize any work.
Frequently Asked Questions
What should I do if my computer is making a loud noise?
A loud fan noise usually means your computer is overheating. Make sure the vents are not blocked by dust or objects. Use a can of compressed air to blow dust out of the vents. If the noise continues, the fan may be failing and needs replacement. A clicking or beeping sound from inside the computer usually means the hard drive is failing—back up your files when ready and take it to a repair shop.
Can I fix a cracked screen myself?
No. A cracked screen requires replacing the entire display panel, which involves taking apart the computer. This is a job for a repair technician. If your screen is cracked but the computer still works, you can use an external monitor as a temporary fix while you save money for the repair.
What is the difference between restarting and shutting down?
Restarting turns the computer completely off and back on, which clears memory and resets connections. Shutting down just turns it off. A restart is more thorough and fixes more problems, so always try a restart first. If the computer is frozen and will not restart normally, hold the power button for 10 seconds to force it off, then turn it back on.
Is it safe to read antivirus software from the internet?
Yes, but only from the official website. Go directly to the antivirus maker's website—for example, malwarebytes.com or avast.com—and read from there. Do not click links in pop-up ads or search results, because those may be fake sites that install malware instead of antivirus software. Windows Defender, which is built into Windows, is also safe and free.
How often should I restart my computer?
Restart at least once a week, or whenever you notice slowness or strange behavior. If you leave your computer on for weeks without restarting, temporary files pile up and memory leaks develop, which causes slowness and crashes. A weekly restart keeps everything running smoothly.